The present invention relates to an improved wood-type golf club head, and more particularly relates to an improvement in mechanical property of a wood-type golf club head having an fiber reinforced plate (FRP) shell.
In the construction of a conventional club head of this type, a metallic sole plate is attached via screws to the sole face of the FRP shell. Alternatively, a sole plate may be inserted into and fixed to a local recess formed in the sole face of the FRP shell. In either case, the sole plate is used for the purposes of weight adjustment and/or protection of the FRP shell.
With such conventional constructions, fixing by screws cannot endure repeated application of impulsive force which acts on the sole plate when driving balls, thereby causing accidental separation of the sole plate during long use. Even when long screws are used for fixing the sole plate, the relatively thin construction of the FRP shell cannot assure reliable fixing of the sole plate during long use.
When a large hole exists in the FRP shell due to requirement in production, at least the part of the FRP shell has to be covered with a metallic sole plate for reinforcement. Such local covering by the sole plate, however, develops shearing force in the plane of contact of the sole plate with the FRP shell and, as a consequence, appreciable effect of reinforcement by the sole plate cannot be expected.
When a sole plate is received in a recess in the sole face of the FRP shell, the construction may well withstand the above-described impulsive force. However, this construction cannot provide full protection over the entire sole face and the peripheral section of the sole face of the FRP shell is left out of the protection by the sole plate. When a metallic sole plate covers the entire sole face of the FRP shell, resultant excessive total weight of the club head disenables free design of weight adjustment.